booze-tools VS Lark

Mmmm... Indirectly... Sophie uses my literate parsing system.

It's not my idea. It's present at least as far back as YACC, "Yet Another Compiler-Compiler", which inspired the name of BISON (another parser-generator named for ungulates). Here's mine, written in Python: https://github.com/kjosib/booze-tools It also has a few extra bits. Feel free to exploit its MIT license to the fullest. I should mention that the design of symbolic reduce-actions was intended to allow one to use the same grammar across multiple host languages. You could even write a driver that does simply build a parse-tree and then hand that off to a separate phase, but in my world I almost always want a bottom-up tree-transduction as first-pass de-sugaring.

Many CS schools have an undergrad class called "compilers" in which you'll implement (from the ground up) either a Scheme or a thing-that-is-like-Java called decaf, or possibly you'll implement Scheme and just call it decaf. If your school does not have such a course, you can get class notes from Texas A&M or Stanford or a variety of other places. (Here's a parser for it.)

Lark supports, and recommends, writing and storing the grammar in a .lark file. We have syntax highlighting support in all major IDEs, and even in github itself. For example, here is Lark's built-in grammar for Python: https://github.com/lark-parser/lark/blob/master/lark/grammar...

You can also test grammars "live" in our online IDE: https://www.lark-parser.org/ide/

The rationale is that it's more terse and has less visual clutter than a DSL over Python, which makes it easier to read and write.

First, let me introduce myself. My name is Erez. You may know some of the Python libraries I wrote in the past: Lark, Preql and Data-diff.

It's not super maintained but you might enjoy building something with ppci, Pure Python Compiler Infrastructure. It has some front-ends and some back-ends. There's also PeachPy for an assembler. People like using Lark for parsing, I hear.

lark, a parsing library where I am somewhat involved has a really nice solution to this: Rules starting with _ are inlined in a post processing step.

Lark is a good library to assist with this.

If I may ask, did you consider Lark, and if so, why wasn't it fit for your purposes?

A grammar provides the high level constructs you need to define the "shape" of your data, and it largely takes care of the rest. Grammar libraries exist in other language (eg. lark or Parsimonius in Python) and they weren't created just to make XML parsing easier.

I made a solid attempt at an Earley parser framework of my own, but apparently to get the most reliable performance from Earley parsing you need to implement Joop Leo's improvement for right-recursive grammars, which nobody has been able to adequately explain to me. I've read Kegler's open letter to Vaillant, I've tried to read other implementations, I've even tried to beat my head against the original academic paper, but I don't have the background knowledge to make sense of it all.